From the book Embedded Computing, it has a ISA chapter, below is the summary of “what is ISA” ISA helps compiler’s life easy. Hardware engineer often saving a few gates or some code, but that hurt the design of compiler ISA can both hide and expose key implementation details to the programmer or compiler Process… Read more

I am developing an Assembler, i think the best way is to embed the test case into the grammer, all those test cases are just one single line of assembly code. But now no way to do this in Antlr grammar. I am thinking to create a maven plugin to pre-process the grammar file. Add… Read more

a super skill to help you understand .init and .fini, just do “LD_DEBUG=libs ./a.out”, read detail http://www.bnikolic.co.uk/blog/linux-ld-debug.html One thing need to remind you, loader pass control to a.out *BEFORE* it calls the fini. read count : 28

discovered something about .init and .fini sections, if you compile your source file into .o, no .init and .fini sections exist. But if you compile your code into target exe, .init and .fini are there. My question is: where does those .init and .fini come from the .o? read count : 8

finally made it: installed the resolver address in GOT[2], now i am able to load up elf binary to memory, execute it, during dynamic loading, it jump to GOT[2]. What i have to do is to make my own resolver works. read count : 13

Description of the first few entries in GOT table GOT[0] : The table’ s entry zero is reserved to hold the address of the dynamic structure, referenced with the symbol _DYNAMIC . This allows a program, such as the dynamic linker, to fi nd its own dynamic structure without having yet processed its relocation entries. This is especially… Read more

My kernel crashed after changed from c to c++, for this bug, a variable value accidentally changed its value, i was not about to know which code changed it. In previous version of GKD, i can turn on the profiling feature to see which memory address has been accessed, but this is not enough because… Read more

This is the tutorial for running testing program for peter-dwarf, there are two programs inside the jar, first one is a command-line program to test peter-dwarf functions, the second one is a program with GUI. 1) Running the command line program This will print out the function name contain the address 0x1600300 in file “kernel”… Read more

One side effect about changing the kernel from c to c++ is that: in the kernel file, the number of dwarf information will increase dramatically from 1,000 to 1,550,000. This let the peter-dwarf parser work slowing to build a tree to display it (But the dwarf parsing still fast). I added the parameter in PeterDwarfPanel… Read more

!!! Nobody can read the dwarf specification and write the dwarf parser without hacking the binutils lab. Dwarf is just too complex and lots of algorithms in it. Now i can use peter-dwarf to parse out my c++ kernel. The dwarf stub that generated by c++ is *MUCH* more complex the c. https://sourceforge.net/p/peter-dwarf/code/358/ fixed these… Read more

my colleague suggested me to use this method to describe how to exact bytes from memory: using pairs of 2-numbers. The formula is that: So if the formula is “1,2”, then x1 is 1, y1 is 2 . That mean it will exact 1 byte then jump to 2 offset and keep do it repeatedly.… Read more

I am doing kernel development in mac, my kernel is loaded up by grub because it relay on multiboot spec. I was unable to install grub in a loopback device on mac, so my mac is running a small linux vm in virtual box, i write a simple php to let me upload my kernel,… Read more

After i build my newlib by “../newlib-2.1.0/configure –target=$TARGET –prefix=$PREFIX”, except the libc.a and crt0.o, i got these linker scripts. I am still thinking which one i should use for my own executables in my OS. elf_i386.x Default linker script, for normal executables elf_i386.xbn Script for -N: mix text and data on same page; don’t align… Read more

When you meet this: Just comment out the following line in /toolchain/include/libelf/sys_elf.h When I build the libelf in mac and in linux, the output sys_elf.h is different, in mac, the above line is not exist, so my OS is able to compile. Peter. read count : 167

I cross compile the libel 0.8.13 on my ubuntu 12.04lts. I used the below command to configure it. The compile process is success and installed it correct. But inside the include/libelf/sys_elf.h, it includes a missing header file (elf.h). Just comment it out, and it will works. read count : 329